1. Technical Field
This invention relates to an air purification system using intense ultraviolet irradiation to break down chemical bonds in toxic compounds and to de-activate pathogens. The method can also be applied to any mass transport, including the purification of water or other fluids containing naturally occurring toxins or those resulting from biological and chemical agents used in warfare.
2. Background Art
Prior art UV disinfecting systems are typically water disinfecting systems where the water is exposed to UV radiation such that the radiation passes through the water, strikes a reflecting surface and then again passes through the water after reflection. The reflecting surfaces, typically polished stainless steel, absorb a significant amount of radiation. Air disinfection systems, such as that described by Halloran (U.S. Pat. No. 3,744,216) employ extended-arc low pressure mercury germicidal lamps within an airstream. Companies such as American Ultraviolet and Steril-Aire manufacture systems that use these lamps within duct of a heating, ventilating, and air conditioning (HVAC) system, providing germicidal action.
In Whitehead, U.S. Pat. No. 4,260,220, a square cross-section hollow tube waveguide is constructed, operating under the principle of total internal reflection (TIR). Each wall section has a planar inner surface and an outer surface having 90° angle longitudinal corrugations. The walls are constructed of transparent dielectric material, such as acrylic or optically clear glass. The Whitehead device is used to transport visible light.
A square cross section light waveguide is known in the art to maximum flux homogeneity in a short distance according to Pritchard (U.S. Pat. No. 3,170,980). These devices are typically employed in projection systems between a the light source and an imaging device such as for example is described in Magarill (U.S. Pat. No. 5,625,738).
Common to the prior art UV disinfection systems is overdosage of ultraviolet (UV) radiation to the air being disinfected, which necessarily increases the size, weight, and power of the resulting equipment. There is a long-felt need to improve the efficiency of such systems and also to provide a portable efficient UV disinfecting system for air.